Florida Gun Law "In Plain English" from www.Packing.org:
Lawful Use Of A Firearm For Defense
A license to carry a firearm is not a license to use it. Under Florida law, you can use deadly force only if you reasonably believe yourself or another person to be in danger of death or serious personal injury, or to prevent the imminent commission of a forcible felony (such as rape, robbery or carjacking). There are two important concepts to remember: The first is the "Duty To Retreat"; this means that if you can avoid the danger by running away, then run away, no matter how you may feel that this affects your honor. The second is the "Castle Doctrine", which means that you do NOT have a "Duty To Retreat" when in your own home or place of business; you can stand your ground and defend your premises and possessions even if you could avoid personal danger by running away.